In May 2009, Liza Marquez, Caruso's ex-girlfriend and the mother of two of his children, named Maria Vianey Guadron, a former nanny for the couple, as a defendant in her lawsuit against Caruso. Marquez alleges that Guadron was spying on behalf of Caruso and after Guardron refused to sign a non-disclosure agreement, Marquez fired her at the end of February 2009.Radar: David Caruso's Ex Sues Nanny (May 5, 2009)

• On April 14, 2009, Austrian-native Heidemarie Schnitzer, 42, was sentenced to seven months in an Austrian prison for harassing David Caruso by sending him approximately 120 menacing letters, including a death threat. Judge Gunther Bohler ruled that after Schnitzer serves her prison term she would then be relocated to an institution for mentally-deranged delinquents. After her sentencing, Schnitzer told television reporters, "the seven months are okay with me, but that I will be sent to such an institution is a real shock."Austrian Times: Verdict Wiped Smile off Caruso Stalker's Face (April 15, 2009)

• Almost three years earlier, Schnitzer wrote to David Caruso, "I'm going to kill you and your butt-ugly Latina whore" after the actor did not respond to her request for an autograph. She later claimed it was just a joke to attract attention.

• In April 2009, court psychiatrist Karin Treichl said Schnitzer has a personality disorder and warned that Schnitzer could engage in similar behavior in the future. Treichl recommended that Schnitzer have at least a year of therapy, "if not, everybody in her surroundings will be a possible victim." Schnitzer has previously threatened others, including her own lawyer.

• Schnitzer's lawyer, Andreas Grabenweger, has appealed the sentence.Austrian Times: Verdict Wiped Smile off Caruso Stalker's Face (April 15, 2009)

• On April 9, [2009, Caruso's ex-girlfriend, Liza Marquez, filed a lawsuit against the actor in Los Angeles Superior Court. Caruso responded through his representative, "that the suit from Liza Marquez is in retaliation for David"s concerns about their children."Radar: David Caruso Blasts Back After Ex-Lover's Lawsuit (April 9, 2009)

• The couple reportedly met in 2004 and began living together in the fall of that year. Marquez claims that Caruso promised to give her an engagement ring but apparently never did. Their relationship ended in October 2007, shortly before Marquez gave birth to their second child.

According to a lawsuit filed by Marquez in April 2009, she was was served with a paternity action upon arriving home after giving birth to the couple's second child. Also according to the court papers, Caruso was supposed to pay Marquez $1 million as part of an August 2008 agreement but did not. The litigation papers include "Breach of Contract/Settlement Agreement, Fraud, Intentional Infliction of Emotional Distress (Domestic Abuse)"Radar: [Sued By Mother of His Children; Shocking Charges(April 9, 2009)

• Caruso's spokesperson said, "Last month David became concerned about the welfare of his children and sought court assistance to redefine David's and Liza's custodial schedules. It now appears that Liza has decided to retaliate by raising false claims against David, which David finds unfortunate since these claims will divert the parties' and the court's attention away from the best interests of the children."Radar: David Caruso Blasts Back After Ex-Lover's Lawsuit (April 9, 2009)

• According to Radar Online, the following allegations were included in a lawsuit filed on April 9, 2009 by Liza Marquez against David Caruso.Radar: [Sued By Mother of His Children; Shocking Charges(April 9, 2009)
• Has a collection of 1970s pornographyRadar: [Sued By Mother of His Children; Shocking Charges(April 9, 2009)
• Asked her to have an abortion during her first pregnancyRadar: [Sued By Mother of His Children; Shocking Charges(April 9, 2009)
• Accused her of wanting to have sex with actor Billy Dee WilliamsRadar: [Sued By Mother of His Children; Shocking Charges(April 9, 2009)
• Domestic abuse while she was pregnant with their second childRadar: [Sued By Mother of His Children; Shocking Charges(April 9, 2009)
• Told other people she was mentally illRadar: [Sued By Mother of His Children; Shocking Charges(April 9, 2009)