Diary of a Perfect Murder - S1-E1
Continuity mistake: Ben Matlock is in his office, angrily polishing his boots while he listens to the interview of the brash prosecutor on TV. The leg of the boot is under, then above, then under his forearm again in the span of three shots. (00:43:30)
Diary of a Perfect Murder - S1-E1
Continuity mistake: When Lockwood is on the stand, Matlock asks him if he is aware of ties with the "American Unified Finance Corporation." As he spells out the name of the company, he moves the side of his hand along the railing in small steps. However, there is a reverse shot in the middle of it where his arm is still and positioned at a different height. (01:24:20)
Diary of a Perfect Murder - S1-E1
Continuity mistake: When Paul Lockwood catches Charlene Matlock and the others at his plant and tells them they are trespassing, Ben eventually says, "Let's go." Lori Lethin pulls away from Andy Griffith two separate times in that shot and the next. (01:19:55)
Diary of a Perfect Murder - S1-E1
Continuity mistake: When Matlock starts implying that Mr. Banning is the one that tipped The Scandal reporters about his client, he clutches the stand with both hands and shuffles back and forth. As the line "frequently pay people to alert them" is spoken, transitioning to a different camera angle, he is all of a sudden no longer clinging to the railing corner. (01:11:15)
Diary of a Perfect Murder - S1-E1
Continuity mistake: When Matlock pretends he's done with Banning, the hotel desk clerk, he walks away from him. Richard Lineback has his hands in his lap in two different ways in the two separate shots, just beginning to stand twice in a row. (01:10:35)
Diary of a Perfect Murder - S1-E1
Continuity mistake: Matlock questions Mrs. Harris at the stand; Andy Griffith keeps switching between a hand in his pants pocket and a hand on the jacket over his hip. (01:06:40)
Diary of a Perfect Murder - S1-E1
Continuity mistake: Prosecutor Burton Hawkins shows People Exhibit B (the murder weapon), doing a fancy twirl, keeping his arm outstretched in the wide shot. His spin concludes in a narrower camera angle; this time, his arm is down. (01:04:15)
Diary of a Perfect Murder - S1-E1
Character mistake: Prosecutor "Death Row" Hawkins finishes speaking with prospective jury member Mr. Cooper and tags in The Defense attorney, saying, "Mr. Matlock, your witness." Naturally, Cooper is not a witness of anything; they are selecting the jury.
Answer: I did not see this episode, but YES. Both prosecution and defense lawyers use investigators to search for and uncover evidence that is legally admissible.