Prosecutors are expected to wrap up their case Friday in the murder trial of George Zimmerman, with Trayvon Martin’s mother likely to be the state’s final witness.

On Wednesday, before a holiday break, jurors heard about Zimmerman’s criminal-justice studies and his interest in police work, as well as testimony from forensic experts.

Zimmerman, 29, is charged with second-degree murder in the Feb. 26, 2012, shooting death of Trayvon, 17, of Miami Gardens. Zimmerman claims self-defense, saying he was attacked by Trayvon in the gated Sanford community where Zimmerman lives and where Trayvon was visiting his father.

Part of the state’s theory in the case is that Zimmerman, a neighborhood-watch leader, acted as a vigilante and wannabe cop, profiling and pursuing an unarmed Trayvon.

Seminole Circuit Judge Debra Nelson cited that theory in allowing the state to call witnesses and present other evidence Wednesday that documented Zimmerman’s previous interest in legal issues and law enforcement.

Zimmerman was one of the “better students” in a criminal-litigation course, the professor, U.S. Army Capt. Alexis Carter, said. He earned an A in the 2011 class, which the instructor said covered on several occasions Florida’s controversial Stand Your Ground law.

In an interview televised last year and played in court this week, Zimmerman said he had never heard of Stand Your Ground until after the shooting.

Defense attorney Don West took his cross-examination of Carter as an opportunity to have the witness explain elements of self-defense. Carter testified that injuries do not have to be life-threatening or even present to make a reasonable claim of self-defense.

“You don’t have to wait until you’re almost dead before you can defend yourself?” West asked.

“No. I would not advise to do that,” Carter replied.

Technical problems slightly delayed the testimony of another of Zimmerman’s Seminole State College professors. Gordon “Scott” Pleasants connected to the courtroom via Skype, but his screen quickly became inundated with call-in requests from pranksters who had been following the trial on TV.

“There is now a really good chance that we are being toyed with,” defense attorney Mark O’Mara said. They moved the interview from Skype to an iPhone projected into a microphone on the witness stand.

Prosecutors also called witnesses who confirmed that Zimmerman applied in 2009 for a job with the Prince William County, Va., police department. His application was rejected because of poor financial credit, Lt. Scott Kearns testified

And in 2010, Zimmerman requested to go on a ride-along with Sanford Police. He wrote on his request form that the experience would help solidify “my chances of a career in law enforcement,” said Jim Krzenski, a Sanford Police administrator.

Jurors ended the day with testimony from two Florida Department of Law Enforcement analysts.

Amy Siewert explained how Zimmerman’s semiautomatic pistol functioned. She testified that the single shot that killed Trayvon was a “contact shot,” meaning the muzzle of the gun was in contact with Trayvon’s hooded sweatshirt when it fired.

On cross-examination, Siewert said she could confirm that the gun was “touching” Trayvon’s hoodie, not that it was “pressing” against it, as prosecutor John Guy noted in his opening argument.