If it's 35,25 degrees Celsius outside and my thermometer reads 35 degrees, it's accurate because it gives the correct temperature, but it isn't precise because it's missing a fraction of a degree. If my thermometer is digital and says 35,25 degrees, then it's precise because it displays readings to the hundredth of a degree. My thermometer would be precise but inaccurate if it read 34,65 degrees instead of 35,25.
In your example, Lara might give precise details about a witness who actually never existed (it was either her imagination or a lie), so her description would be inaccurate. On the other hand, she might give a few accurate details about a real witness (hair color, height, clothing, etc.) but not be precise about the gender, facial characteristics, etc. because she was too far away and it was getting dark.